Supplemental Table S1. Geometric means of plasma prolactin by selected variables stratified by years between sample collection and baseline interview among postmenopausal women, the Singapore Chinese Health Study

< 7 years / ≥ 7 years
n / Geometric Mean* / P value / n / Geometric Mean* / P value
Age at menarche, yr
<13 / 16 / 7.82 / 35 / 9.46
13-14 / 65 / 7.08 / 119 / 6.74
>14 / 62 / 6.86 / 0.394 / 145 / 6.68 / 0.015
Years between menarche and first birth, among parous women, quartiles
<9.5 / 51 / 7.22 / 117 / 6.62
9.5- <10.5 / 22 / 5.88 / 33 / 7.16
10.5 - <15.5 / 41 / 7.22 / 89 / 6.88
≥15.5 / 25 / 7.28 / 0.788 / 39 / 8.78 / 0.042
Years from menarche to menopause, quartiles
<34.5 / 42 / 7.50 / 90 / 7.18
34.5 - <38.5 / 47 / 6.58 / 104 / 6.40
38.5 - <40.5 / 36 / 6.80 / 76 / 6.64
≥40.5 / 18 / 8.00 / 0.987 / 29 / 10.04 / 0.130
Sleep, hours/day
≤5 / 19 / 6.34 / 30 / 7.66
6 / 30 / 6.08 / 90 / 6.42
7 / 48 / 6.84 / 98 / 6.54
8 / 34 / 8.24 / 67 / 7.94
≥9 / 12 / 8.94 / 0.006 / 14 / 8.48 / 0.123
Estrone, tertiles, pg/mL
<21.66 / 47 / 7.90 / 99 / 7.40
21.66-<30.6 / 57 / 7.26 / 92 / 6.94
≥30.6 / 39 / 5.94 / 0.011 / 106 / 6.60 / 0.168
SHBG, tertiles, nmol/mL
<33.70 / 46 / 6.36 / 100 / 6.68
33.70-<48.70 / 44 / 6.84 / 107 / 6.86
≥48.70 / 53 / 7.96 / 0.028 / 92 / 7.50 / 0.162

*Geometric means are adjusted for age at biospecimen collection, time since last meal, and time of specimen collection.

All Ps for interaction are not significant.

Supplemental Table S2. Geometric means of plasma prolactin by selected variables stratified by fasting status among postmenopausal women, the Singapore Chinese Health Study

Fasting samples (9+ hours) / Non-fasting samples (< 9 hours)
n / Geometric Mean* / P value / n / Geometric Mean* / P value
Age at menarche, yr
<13 / 21 / 10.12 / 30 / 8.30
13-14 / 42 / 7.02 / 142 / 6.84
>14 / 50 / 6.66 / 0.012 / 157 / 6.72 / 0.136
Years between menarche and first birth, among parous women, quartiles
<9.5 / 39 / 6.38 / 129 / 6.88
9.5- <10.5 / 11 / 7.24 / 44 / 6.44
10.5 - <15.5 / 37 / 7.16 / 93 / 6.96
≥15.5 / 17 / 9.56 / 0.044 / 47 / 7.78 / 0.294
Years from menarche to menopause, quartiles
<34.5 / 34 / 8.00 / 98 / 6.96
34.5 - <38.5 / 37 / 6.46 / 114 / 6.44
38.5 - <40.5 / 27 / 6.64 / 85 / 6.78
≥40.5 / 15 / 9.96 / 0.606 / 32 / 9.02 / 0.122
Sleep, hours/day
≤5 / 12 / 6.72 / 37 / 7.28
6 / 42 / 6.66 / 78 / 6.36
7 / 35 / 7.06 / 111 / 6.38
8 / 22 / 9.50 / 79 / 7.62
≥9 / 2 / 11.48 / 0.021 / 24 / 8.54 / 0.061
Estrone, tertiles, pg/mL
<21.66 / 24 / 7.78 / 122 / 7.48
21.66-<30.6 / 38 / 7.26 / 111 / 6.98
≥30.6 / 49 / 7.10 / 0.553 / 96 / 6.14 / 0.009
SHBG, tertiles, nmol/mL
<33.70 / 37 / 6.76 / 109 / 6.54
33.70-<48.70 / 42 / 6.92 / 109 / 6.82
≥48.70 / 34 / 8.66 / 0.076 / 111 / 7.36 / 0.112

*Geometric means are adjusted for age at biospecimen collection, time since last meal, and time of specimen collection.

All Ps for interaction are not significant.

Supplemental Table S3.Geometric mean of plasma prolactin by the time interval between the last meal intake and of the blood draw among postmenopausal women, the Singapore Chinese Health Study

Time interval between the last meal intake and the blood draw / n / Geometric mean, ng/mL / p value
8:00-9:59 / 123 / 7.08
10:00-10:59 / 120 / 6.88
11:00-11:59 / 113 / 7.16
12:00-12:59 / 76 / 6.92
13:00-15:59 / 10 / 6.70 / 0.9

*Geometric means are adjusted for age at blood draw and time since last meal.

Supplemental Table S4. Geometric means of plasma prolactin by selected reproductive characteristics and sleeping hours among postmenopausal women, the Singapore Chinese Health Study

n / Geometric Mean* / P value / % difference (P value)†
Age at menarche, yr
<13 / 51 / 9.16
13-14 / 184 / 6.76
>14 / 207 / 6.64 / 0.009 / -27.5 (<0.001)
Years between menarche and first birth, among parous women, quartiles
<9.5 / 168 / 6.56
9.5- <10.5 / 55 / 6.34
10.5 - <15.5 / 130 / 6.92
≥15.5 / 64 / 8.60 / 0.011 / 31.2 (0.003)
Years from menarche to menopause, quartiles
<34.5 / 132 / 7.12
34.5 - <38.5 / 151 / 6.42
38.5 - <40.5 / 112 / 6.62
≥40.5 / 47 / 9.24 / 0.178 / 29.7 (0.012)
Sleep, hours/day
≤5 / 49 / 7.14
6 / 120 / 6.26
7 / 146 / 6.50
8 / 101 / 7.94
≥9 / 26 / 8.98 / 0.009 / 26.1 (0.119)

*Geometric means are adjusted for age at biospecimen collection, time since last meal, time of specimen collection, plasma free-estradiol, testosterone, SHBG, and androstenedione.

†% difference between last versus first listed categories.

Supplemental Table S5. Geometric means of plasma prolactin by selected variables stratified by BMI among postmenopausal women, the Singapore Chinese Health Study

BMI < 24.0 kg/m2 / BMI ≥ 24.0 kg/m2
n / Geometric Mean* / P value / n / Geometric Mean* / P value
Age at menarche, yr
<13 / 37 / 9.50 / 14 / 7.60
13-14 / 109 / 6.70 / 75 / 7.16
>14 / 137 / 6.74 / 0.014 / 70 / 6.64 / 0.287
Years between menarche and first birth, among parous women, quartiles
<9.5 / 99 / 6.76 / 69 / 6.80
9.5- <10.5 / 23 / 6.30 / 32 / 6.82
10.5 - <15.5 / 92 / 6.88 / 38 / 7.34
≥15.5 / 50 / 9.48 / 0.069 / 14 / 7.00 / 0.564
Years from menarche to menopause, quartiles
<34.5 / 73 / 7.44 / 59 / 7.00
34.5 - <38.5 / 110 / 6.46 / 41 / 6.42
38.5 - <40.5 / 70 / 6.60 / 42 / 6.96
≥40.5 / 30 / 9.74 / 0.231 / 17 / 8.24 / 0.430
Sleep, hours/day
≤5 / 30 / 7.00 / 19 / 7.34
6 / 79 / 6.78 / 41 / 5.74
7 / 90 / 6.66 / 56 / 6.38
8 / 68 / 7.78 / 33 / 8.58
≥9 / 16 / 7.64 / 0.231 / 10 / 11.40 / 0.002
Estrone, tertiles, pg/mL
<21.66 / 95 / 7.66 / 51 / 7.34
21.66-<30.6 / 104 / 6.84 / 45 / 7.62
≥30.6 / 82 / 6.54 / 0.066 / 63 / 6.26 / 0.097
SHBG, tertiles, nmol/mL
<33.70 / 101 / 6.68 / 45 / 6.40
33.70-<48.70 / 93 / 6.98 / 58 / 6.64
≥48.70 / 89 / 7.54 / 0.152 / 56 / 7.82 / 0.051

*Geometric means are adjusted for age at biospecimen collection, time since last meal, and time of specimen collection.

All Ps for interaction are not significant.

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